Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

alpha2-Heremans Schmid glycoprotein (AHSG), also designated fetuin-A, is an abundant plasma protein that is expressed in hepatocytes. AHSG/fetuin-A has diverse biological functions including regulation of calcium homeostasis and inhibition of insulin receptor tyrosine kinase activity. The aim of this study was to detect single nucleotide polymorphisms (SNPs) of the AHSG gene that can be involved in regulation of AHSG/fetuin-A expression. By a cycle sequencing method, two common SNPs in the promoter region of AHSG gene, -799A/T (rs2248690, dbSNP ID) and -425G/T (rs2077119), were identified. A reporter gene assay using HepG2 cells showed that the -799A allele had significantly higher promoter activity compared with the -799T allele. The overexpression of c-Fos/c-Jun significantly repressed transcriptional activity and a gel shift assay showed that the -799T DNA fragment had a greater affinity for transcription factor AP-1 than the -799A. In 40 unrelated healthy subjects, serum AHSG/fetuin-A levels increased with the following order of genotypes: -799TT<-799AT<-799AA (mean+/-S.E.M.; 222.1+/-11.0, 291.8+/-8.1, and 349.0+/-13.0 microg/ml, respectively, P<0.001). In conclusion, SNP rs2248690 in the promoter region of the AHSG gene affects the AHSG gene transcription, possibly by producing different association with AP-1.
Diabetes Res Clin Pract 2008 Jan
PMID:A promoter polymorphism of the alpha2-HS glycoprotein gene is associated with its transcriptional activity. 1788 58

Aortic stiffening and aortic calcification are risk factors for cardiovascular events in hemodialysis (HD) patients, and these 2 risk factors are interrelated. Sevelamer decreases aortic calcification but its effect on aortic stiffness has not been investigated previously. Thirteen HD patients commencing sevelamer treatment and 13 matched controls were followed for 11 months. Aortic pulse wave velocity (PWV), augmentation index (AIx), and levels of inhibitors of vascular calcification (fetuin-A, matrix-GLA-protein, osteoprotegerin/RANKL) were measured at baseline and at the end of follow-up, and the differences between the groups were compared. Determinants of the changes in PWV during follow-up were assessed by multivariate linear regression. At baseline, PWV was 9.93 (2.10) m/s in sevelamer-treated patients and 9.20 (2.84) m/s in control patients (p=0.464). By the end of follow-up, PWV decreased by 0.83 (2.3) m/s in sevelamer-treated patients while it increased by 0.93 (1.88) m/s in controls (p=0.042). The direction of changes in AIx were similar, but not statistically significant. There were no significant differences in the levels of inhibitors of calcification either at baseline or during follow-up. In multivariate linear regression sevelamer treatment, diabetes, heart rate, and C-reactive protein were related to the change in PWV. These data suggest that sevelamer treatment is associated with an improvement in aortic stiffness in HD patients, but it does not seem to affect serum levels of inhibitors of vascular calcification.
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PMID:Effect of sevelamer on aortic pulse wave velocity in patients on hemodialysis: a prospective observational study. 1789 5

There is increasing evidence to suggest that the initiation of vascular calcification is an active process involving vascular smooth muscle cell (VSMC) apoptosis and trans-differentiation into calcifying cells. This active process results in the deposition of an osteogenic extracellular matrix and may be exacerbated by a reduction in the levels of one or more native calcification inhibitors (such as fetuin A and pyrophosphate). Here, we present data which strongly suggest that the regression of vascular calcification might also be an active cellular process involving osteoclast-like cells. However, the presence of osteoclast like cells in the vascular wall is rather limited. To explain this rarity of osteoclast-like cells, we recently observed that the same factors, which promote the trans-differentiation of VSMCs into osteoblast-like cells are also capable of inhibiting the in vitro differentiation of monocytes/macrophages into osteoclast-like cells. An imbalance between osteoblast-like and osteoclast-like cell activities would therefore favour the occurrence of a pathological calcification process in vessel walls. Our new data are strongly evocative of a vascular remodelling process similar to that observed in bone tissue. To confirm this hypothesis, strategies for activating osteoclasts in the vascular wall (with a view to preventing or reversing vascular calcifications) are required.
Diabetes Metab 2008 Feb
PMID:The pathophysiology of vascular calcification: are osteoclast-like cells the missing link? 1835 22

Traditional risk factors such as hypertension, diabetes, dyslipidemia, obesity and metabolic syndrome, as well as additional nontraditional risk factors, can damage the kidney directly and by promoting intrarenal atherogenesis. Evidence indicates that increased oxidative stress and inflammation may mediate most of the effects of risk factors on the kidney. Clinical studies have demonstrated a relationship between oxidative stress and inflammatory biomarkers, and a few studies indicate an inverse correlation of oxidative stress biomarkers with estimated glomerular filtration rate (eGFR). Further, surrogate indexes of atherosclerosis such as intima-media thickness and aortic pulse wave velocity have been demonstrated to be related to plasma concentrations of markers of endothelial activation, inflammation and fibrosis in patients with different stages of chronic kidney disease (CKD). Moreover, plasma concentrations of high-sensitivity C-reactive protein have been shown to be increased and related to left ventricular mass in CKD individuals having left ventricular hypertrophy. In contrast, in these patients, decreases in fetuin-A plasma levels have been reported. Considering the complex background of the pathophysiological changes characterizing CKD patients, we can consider cardiovascular disease a multifactorial complication of CKD.
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PMID:Oxidative stress, inflammation and cardiovascular disease in chronic renal failure. 1844 11

The articles providing answers to the questions on vascular calcification of most interest from a clinical point of view were selected. 1. How is it measured?: Studies showing the clinical utility of different tools to quantify it were analyzed. 2. What does it measure?: Both in dialysis patients and the general population, vascular calcification and arterial stiffness are prognostic factors for morbidity and mortality. Other markers such as fetuin-A are associated with mortality in patients on hemodialysis but not in patients in early stages of chronic kidney disease. 3. What causes it?: In two selected studies, it was demonstrated again that low bone turnover and diabetes cause cardiovascular disease and vascular calcification, respectively. 4. How is it treated?: There is still no clinical evidence of regression of vascular calcification. However, a prospective study in new hemodialysis patients showed that sevelamer compared to calcium compounds slows the progression of vascular calcification and confers greater survival. A study comparing both compounds in chronic hemodialysis patients showed that sevelamer only had a benefit on survival in patients older than 65 years. It remains to be demonstrated whether the good experimental results of paricalcitol and cinacalcet are confirmed in prospective clinical studies.
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PMID:[Clinical advances in vascular calcification]. 1884 18

Fetuin-A is a hepatic secretory protein that promotes bone mineralization in vitro. Whether fetuin-A levels are associated with BMD in humans is unknown. The Health Aging and Body Composition study enrolled 3075 well-functioning black and white persons 70-79 yr of age and measured BMD. This cross-sectional study measured serum fetuin-A using ELISA among a random sample of 508 participants within sex and race strata. Multivariate linear regression analysis evaluated the associations of fetuin-A with BMD. Among women (n = 257), higher fetuin-A levels were significantly associated with higher total hip (p = 0.02), lumbar spine (p = 0.03), and whole body BMD (p = 0.01) in models adjusted for age, race, diabetes, alcohol and tobacco use, physical activity, body mass index, C-reactive protein levels, calcium supplement, and estrogen use. For example, each SD (0.38 g/liter) higher level of fetuin-A was associated with 0.016 g/cm(2) higher total hip areal BMD. The association was of similar magnitude and direction for femoral neck BMD but did not reach statistical significance (p = 0.11). In contrast, among men (n = 251), fetuin-A had no significant associations with total hip (p = 0.79), lumbar spine (p = 0.35), whole body (p = 0.46), or femoral neck BMD (p = 0.54) in multivariable models. We conclude that higher fetuin-A levels are independently associated with higher BMD among well-functioning community-dwelling older women but not older men. Future studies should evaluate whether fetuin-A may refine fracture risk assessment in older women.
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PMID:Fetuin-A and BMD in older persons: the Health Aging and Body Composition (Health ABC) study. 1901 89

Vascular calcium deposition in end-stage renal disease occurs commonly, but its relation to cardiovascular risk factors and fetuin-A levels in African Americans is not known. Compliant African American patients who were undergoing hemodialysis (HD; n = 17) agreed to undergo 64-slice multidetector computed tomography for the assessment of coronary artery calcium score (CACS). The relation between traditional cardiovascular risk factors (i.e., age; gender; dialysis vintage; history of diabetes; means of the previous 3 years of weekly predialysis blood pressure values and hemoglobin levels; means of monthly values of calcium, phosphorus, alkaline phosphatase, uric acid; and albumin; and means of quarterly measurements of parathyroid hormone and lipids) and fetuin-A levels and CACS was explored using univariate analyses. Serum phosphorus levels over the previous 3 years were well controlled. The CACS range was 0 to 3,877 Agatston units (mean 996, median 196). Among the tested variables, only fetuin-A was significantly and inversely associated with CACS (standardized beta = -0.64, 95% confidence interval -18.09 to -3.62, p = 0.006). There was no association between age and fetuin-A level (standardized beta = -0.02, 95% confidence interval -0.10 to 0.23). In conclusion, African-American patients who were undergoing long-term hemodialysis and with good phosphorus control exhibited a strong inverse correlation between fetuin-A level and CACS that was independent of age.
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PMID:Relation of serum fetuin-A levels to coronary artery calcium in African-American patients on chronic hemodialysis. 1910 Dec 28

Extrarenal calcifications, particularly affecting the cardiovascular system, are common observations which can be a source of serious complications in patients with chronic renal disease, especially those on dialysis. In these patients, cardiovascular disease - myocardial infarction, arrhythmia, calcified valvulopathy, stroke, peripheral ischemic arteriopathy, calciphylaxy, etc. - is the leading cause of death (more than 50%). These complications are closely related to the presence of vascular calcifications (VC) which are much more frequent, severe, and progressive than in the general population. Previously, these calcifications were considered to arise via a passive process within the context of comorbid conditions without specific signs of gravity: high blood pressure, atherosclerosis, aging, diabetes, smoking, dyslipidemia, chronic micro-inflammation, hyperhomocysteinemia, disorders of calcium-phosphorus metabolism. It is now established that VC arise via a complex, probably regulated, active process analogous to the processes leading to bone formation and/or remodeling. New insight provided by a large body of work designed to ascertain the mechanisms underlying the onset of VC has enabled the development of new diagnostic and therapeutic approaches. It is now possible to identify factors clearly favoring the formation of VC: TNF-alpha (which stimulates cell necrosis/apoptosis), CRP, oxidized lipids, AGEs, leptin, inorganic phosphate, high calcium-phosphorus product (CaxPO(4)), calcium, 1,25-OH(2)D(3) and Vitamin D(3), PTHrP (via an intracrine pathway), cyclic AMP, TGF-beta, bone morphogenic protein 2 (BMP2) and factors protective against the formation of VC: magnesium, HDL, inorganic pyrophosphate, albumin, ahsg/fetuin A, osteopontin (OPN), osteoprotegerin (OPG), osteonectin (ON), bone morphogenic protein 7 (BMP7), klotho, PTHrP (via a paracrine pathway), matrix gla protein (MGP), PTH (via Msx2) and vitamin K. In conclusion, until recently, neglected disorders of calcium-phosphorus metabolism are currently recognized as the main actors in the process leading to vascular mediacalcosis in patients with chronic kidney failure.
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PMID:[Origin of the mediacalcosis in kidney failure]. 1934 26

Obesity-resistance in AHSG-knockout mice indicate an important role of alpha2-Heremans-Schmid glycoprotein/fetuin-A (AHSG) in the development of obesity. We studied whether genetic variation within AHSG affects whole-body adiposity and regional fat distribution in humans. We genotyped 321 subjects at increased risk for type 2 diabetes for five single nucleotide polymorphisms (SNP) rs2248690, rs4831, rs2070635, rs4917, and rs1071592. Body fat distribution and ectopic hepatic and intramyocellular lipids were assessed by magnetic resonance techniques. AHSG levels were determined by immunoturbidimetry. The five chosen SNPs covered 100% of common genetic variation (minor allele frequency >/=0.05) within AHSG (r (2)>/=0.8). All SNPs were significantly associated with AHSG levels (p<0.0001), except for rs4831 (p=0.9) after adjustment for gender, age, and body mass index (BMI). AHSG levels were associated with liver fat content (p=0.0160) and BMI (p=0.0247) after adjustment for gender and age. While rs2248690 was nominally associated with BMI in the dominant model (p=0.0432), none of the SNPs was associated with regional fat distribution. Common genetic variation within AHSG does not appear to influence regional body fat distribution, but may affect whole-body adiposity in humans.
Exp Clin Endocrinol Diabetes 2009 Sep
PMID:AHSG gene variation is not associated with regional body fat distribution--a magnetic resonance study. 1935 88

Considerable scientific progress in the pathogenesis of vascular calcification that has accrued in recent years is reviewed in this article. Factors regulating mesenchymal cell differentiation and their role in the neointimal calcification of atherosclerosis and the vascular media calcification observed in chronic kidney disease and diabetes are discussed, as is the role of bone regulatory proteins in bone mineralization and vascular calcification. This includes recent studies related to fetuin-A, and the discovery of a new circulating hormone involved in regulating phosphate homeostasis and sensing skeletal hydroxyapatite precipitation. Finally, the relationship between skeletal mineralization and vascular mineralization is discussed in terms of their links, especially through serum phosphate concentrations.
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PMID:The pathogenesis of vascular calcification in the chronic kidney disease mineral bone disorder: the links between bone and the vasculature. 1937 6


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